Handheld High Speed Swept Source Optical Coherence Tomography at 1050nm

Abstract

 

Purpose:

 

A compact handheld optical coherence tomography (OCT) would allow imaging to be performed in settings outside of a traditional ophthalmic clinic setting such as primary care, intensive care, and in the field. However, artifacts from the combination of both operator and patient motion limit the feasibility of handheld systems. We have developed a high speed handheld system with software motion correction to address these limitations.

 

Methods:

 

Images were acquired of the human retina with a handheld scanner using high speed short cavity and VCSEL swept source light sources at 1050nm wavelength from 100 kHz to 350 kHz axial scan rates. The high imaging speed allows data to be collected in a shorter period of time when compared to commercial systems. All the scan patterns were acquired in one second or less to limit the effects of motion. Orthogonal raster scan patterns were post-processed with custom registration software to correct motion artifacts and increase the image quality.

 

Results:

 

The high imaging speed reduces the bulk motion artifacts in the images acquired from the handheld scanner. The 3D and 2D registered images of the retina show a further reduction in motion and an increased signal due to averaging. Imaging at 1050nm wavelength also provides deeper penetration into the retina compared to standard systems at 800nm.

 

Conclusions:

 

Handheld systems require high imaging speeds for the reduction of motion artifacts. Registration and motion correction results in increased image quality. These technologies will enable handheld OCT to be more viable for use in settings outside of the ophthalmology clinic.  

 

Keywords: imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound) • image processing